I've just run through this task to refresh my memory and after taking another look at your screenshots, your chart name shows as "Incident Overview" and not "Open Incidents by Priority" which leads me to believe that step 7 has been missed/not followed fully. I've tried to highlight each location that needs to be updated in the screenshots below and by using example text.
This image shows what should be updated after updating the chart title (step 6):
This image shows what should be updated after updating the chart name via the Details panel icon highlighted by the arrow (step 7):
I've also noticed from your screenshots that you haven't impersonated Platform User, this might not be a issue but from a troubleshooting perspective, I would double check that you have updated both the chart title AND the chart name. If both of those look correct, impersonate Platform User and follow all of the steps again.
If it's still failing to validate after that then you might need to raise a support case if you're 100% sure that you have followed all of the steps exactly as outlined in the task instructions.
NOTE: I've also spotted that you're currently working through the Xanadu version of this course, there is a Zurich release version which would be better for you to complete as it is newer and more up to date.
